CN1555115A - Digital high votage parallel reactor longitudinal protection with end braking - Google Patents
Digital high votage parallel reactor longitudinal protection with end braking Download PDFInfo
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Abstract
This invention relates to the longitudinal difference protection for high-voltage parallel reactors in power system, among which, the ratio brake longitudinal difference property is composed of differential quick-break, ratio brake and high-value ratio property. In order to guarantee the protection of correct operation in the transient state process of extra-high voltage and super-high voltage net, this protection has a reactor air detection function, a secondary circuit gap breakage criterion of TA and TA DC saturation criterion so as to make up of a complete end brake digital high voltage parallel reactor longitudinal protection, among which, the ratio brake applies three-section polygon property, the high voltage ratio applies traditional two-section polygon property, the TA secondary circuit gap breakage applies the method of combining zero-sequence current and a phase current and TA DC saturation criterion applies waveform identification theory helped by harmonic wave analysis.
Description
Technical field
The present invention relates to field of power, relate more specifically to the method for high-voltage shunt reactor relaying protection.
Background technology
At first, according to briefly describing correlation technique of the present invention below with reference to document.
1. congratulate tame Lee etc., " extra-high voltage transmission line relaying protection allocation plan, Automation of Electric Systems ", 2002 the 24th phases
2. Wang Wei is thrifty, " electric main equipment Principles of Relay Protection and application ", in January, 2002 second edition
The superhigh pressure of 330kV ~ 750kV, ultra high voltage system, the power delivery capacity is big, and transmission losses is little, in long distance, large capacity transmission engineering, has overwhelming superiority, be the key rack in the electric power system, its safe and stable operation is the major issue that is related to national economy.Different with the general high voltage power transmission line, the task of extra-high voltage transmission line relaying protection at first is to guarantee not produce the overvoltage that jeopardizes equipment and insulator, secondly is to guarantee system stability.
The distributed capacitance of extra high voltage line produces very big capacitive reactive power, the capacitance current of the 750kV circuit that 500km is long can reach the 50%[1 of rated load electric current], therefore must install shunt reactor absorbs this capacitive power, the switching overvoltage of restriction system, the latent power supply capacitance current in the time of also can limiting single-pole reclosing.
For guaranteeing the safe operation of high-voltage shunt reactor, need installing high-voltage shunt reactor protective device.When this protective device is judged reactor generation internal fault; if calculating, overvoltage in advance shows that the excision of high-voltage shunt reactor internal fault may cause that unallowable overvoltage or high-voltage shunt reactor head end do not have definite purpose circuit breaker, needs the circuit breaker of the circuit of tripping simultaneously both sides.Therefore, the high-voltage shunt reactor protection is the important component part of superhigh pressure and extra-high voltage grid, if incorrect operation in service, consequence is hardly imaginable.
The phase fault of reactor internal ground fault and lead-in wire (2 ground connection of instantaneity) fault is a reactor common faults form, and longitudinal difference protection is the main protection of these two kinds of failure modes.Longitudinal difference protection almost becomes the main protection of all voltage levels element protections because of its high reliability, quick-action, selectivity and sensitivity.But high-voltage shunt reactor has the characteristics of himself, should not indiscriminately imitate the existing vertical difference principle of other element protection, and therefore improving the longitudinal difference protection performance is one of key technology of high-voltage shunt reactor protection.
The homemade digital high-voltage shunt reactor protection of using in the electric power system has only south WDK-600 microcomputer reactor protective device certainly at present.The two-period form braking characteristic is adopted in its vertical poor (phase-splitting is differential) protection, and its stalling current adopts the maximum of first and last end electric current.Braking action is very big when internal fault takes place like this, is to guarantee protection sensitivity minimum working current and the ratio brake slope De Taigao that all can not adjust.This paper improves at this situation, when improving internal fault sensitivity, and the reliability of protecting when increasing external disturbance.
Summary of the invention
Be protection high-voltage shunt reactor Inside coil and lead-out wire earth fault or lead-out wire phase fault, proposed the digital longitudinal difference protection of end braking.Fig. 1 is the vertical difference of the ratio brake characteristic of reactor, is made up of differential quick-break, ratio brake and high value ratio-restrained characteristic.Wherein ratio brake adopts three sections broken line characteristics, and high value ratio brake adopts two sections traditional broken line characteristics, the starting current ICDH and the ratio brake coefficient KIDH program internal fixation of high value ratio brake correspondence, and the user exempts to adjust.This protection has perfect air-drop judgement, the saturated judgement of TA direct current, the unusual arbitration functions of TA.
The invention provides a kind of method of getting the reactor end current as the digital longitudinal difference protection of stalling current, the method comprising the steps of: the reactor protection device is sampled to the current waveform of current transformer and is obtained current instantaneous value; Obtain the plural form of each magnitude of current by the recurrence fourier algorithm; According to the automatic calculated equilibrium coefficient of current transformer (hereafter TA) no-load voltage ratio of user's input, and export this coefficient for user's verification; Calculate differential current and stalling current according to formula 4; By formula 1 described later, formula 2, formula 3 described operation equations, add air-drop criterion, the saturated criterion of TA direct current and the unusual criterion of TA and constitute the complete digital longitudinal difference protection of end braking.
Description of drawings
Fig. 1 has shown reactor longitudinal difference protection characteristic of the present invention;
Fig. 2 has shown reactor longitudinal difference protection logic diagram of the present invention.
Fig. 3 has shown typical reactor system wiring figure.
Specific embodiments
The present invention realizes the digital high-voltage shunt reactor longitudinal difference protection of end braking according to following formula, and its operating characteristics please refer to Fig. 1, and the logical relation between the following formula please refer to Fig. 2, and the system wiring figure of reactor is with reference to figure 3.
At first, the operation equation of differential quick-break is seen formula (1), wherein I
DzBe operating current, I
SDBe the quick-break current ration.
I
dz＞I
SD (1)
Secondly, the operation equation of ratio brake differential protection is seen formula (2):
Wherein: I
ZdBe stalling current, KID1, KID2, KID3 are respectively the ratio brake slope of each section, and wherein KID1 and KID3 device internal fixation are 0.2 and 0.7, and KID2 is adjusted by the user.IB1, IB2 are respectively keen current, and wherein IB1 device internal fixation is 0.5I
R2ln(I
R2lnBe the terminal secondary rated current of reactor), IB2 is adjusted by the user.I
CDBe differential starting current definite value.
Large-scale reactor is generally single-phase type, so adopt above-mentioned differential characteristic mutually to every.When arbitrary when satisfying formula (1) or formula (2) mutually, differential quick-break or biased differential protection action.The syllogic biased differential protection is through saturated locking of TA direct current and TA abnormal obliteration, and wherein the saturated locking of TA direct current is fixing drops into, and the TA abnormal obliteration is selected by control word by the user.
Because of the saturated protection deferred action of TA direct current, be provided with the high value biased differential protection that is not subjected to the saturated locking of TA direct current during for fear of inner catastrophe failure, corresponding operation equation is seen formula (3):
Operating current I
DzWith stalling current I
ZdComputing formula see formula (4), wherein
Be reactor head end electric current,
Be the reactor end current; Be positive direction all to flow into reactor.
Differential each side is carried out balance by software, differential current I because of the different imbalances that produce of TA no-load voltage ratio
DzWith stalling current I
ZdBe the result of calculation after Balance Treatment.Employing formula (4) stalling current is only chosen the algorithm of end current, and protection has very high sensitivity during internal fault, during external fault, and differential not malfunction of assurance.
Because during the reactor internal ground fault, fault phase end current approaches zero, Braking Action None; And be incorporated into the power networks moment at reactor, when passing through property electric current is big, bigger braking action is arranged.Therefore with end current as the longitudinal difference protection scheme of stalling current with first and last end difference between current is compared as the scheme of stalling current, can improve the sensitivity of internal fault.
Because reactor in the air-drop process, contains bigger aperiodic component in the transient state waveform of sky charging stream, cause the appearance of TA direct current saturated conditions.For avoid occur in when air-drop differential circuit than the large unbalance amount, software setting has TA direct current saturation detection function on the one hand.Software also is provided with the air-drop measuring ability on the other hand, suitably improves differential definite value when detecting reactor current and grow out of nothing automatically, prevents because of impulse current makes the longitudinal difference protection malfunction, can guarantee to drop simultaneously longitudinal difference protection correct operation when internal fault again.
Reactor is a load element, and in the transient process of disturbance, power frequency (interchange) electric current that flows through reactor can be very not big outside reactor external area error or other district, thereby deficiency is so that the saturated longitudinal difference protection malfunction that makes takes place TA.And the DC component that flow through reactor this moment generally can be very big and also decay slowly, DC component is easy to make TA saturated (claiming that direct current is saturated), if reactor first and last end TA characteristic is inconsistent, an end is saturated and the other end is unsaturated, then longitudinal difference protection may malfunction.Therefore different with the longitudinal difference protection of other element, guarantee high-voltage shunt reactor longitudinal difference protection reliability service, need the perfect saturated criterion of TA direct current.
The saturated criterion of direct current adopts waveform recognition to combine with harmonic analysis, carries out the method for fault tolerant re-judging:
1) phase current difference stream first-harmonic is 0.15I greater than threshold value
R2ln
2) the phase current difference flows 2 subharmonic ratio greater than 10%, and the triple-frequency harmonics ratio is less than 10%;
3) phase current difference stream waveform deflection time shaft one side, promptly
S wherein
+And S
-Be respectively positive sampled value integration and negative sampled value integration in differential current one cycle;
4) phase current is greater than 1.5I
R2lnThe time remove the saturated differentiation of TA direct current.
The TA secondary circuit is frequent in the scene occurs like non-the breaking but not the phenomenon of thorough broken string of breaking, and a lot of longitudinal difference protection is only considered the thorough situation about breaking of TA, is unable to undergo seemingly disconnected non-disconnected test.This device has perfect TA abnormal detection function, guarantees not malfunction of differential protection under the seemingly disconnected non-disconnected situation of TA.The criterion that TA is unusual:
1) reactor first and last end TA, self-produced zero stream of an end is big, and self-produced zero stream of the other end is little;
2) the big end of self-produced zero stream has a phase current to reduce, the three-phase current no change of other phase of this end and the other end;
3) reactor first and last end three-phase totally six electric currents all less than 1.1 times of rated current;
4) no residual voltage.
For the longitudinal difference protection of high-voltage shunt reactor, the present invention has improved the sensitivity that internal fault is differentiated, the reliability of protecting when increasing external disturbance simultaneously greatly.
Claims (7)
1. method of getting the reactor end current as the digital longitudinal difference protection of stalling current; the vertical difference of the ratio brake characteristic of forming reactor by differential quick-break, ratio brake and high value ratio-restrained characteristic; wherein ratio brake adopts three sections broken line characteristics; high value ratio brake adopts two sections traditional broken line characteristics; the starting current ICDH and the ratio brake coefficient KIDH program internal fixation of corresponding high value ratio brake, the method comprising the steps of:
The reactor protection device is sampled to the current waveform of current transformer and is obtained current instantaneous value;
Obtain the plural form of each magnitude of current by the recurrence fourier algorithm;
According to the automatic calculated equilibrium coefficient of TA no-load voltage ratio of user's input, and export this coefficient for user's verification;
Calculate differential current and stalling current;
The reactor air-drop is differentiated;
Reactor two ends TA secondary circuit intermittence broken string is differentiated;
The saturated differentiation of TA direct current;
The longitudinal difference protection logic is judged in phase-splitting.
2. method as claimed in claim 1 is wherein calculated operating current I according to following formula
DzWith stalling current I
Zd:
Wherein
Be reactor head end electric current,
Be the reactor end current; Be positive direction all to flow into reactor.
3. method as claimed in claim 1, wherein carry out the action judgement of differential quick-break according to following formula:
I
dz＞I
SD
I wherein
DzBe operating current, I
SDBe the quick-break current ration.
4. method as claimed in claim 1, wherein carry out the action judgement of ratio brake differential protection according to following formula:
Wherein: I
ZdBe stalling current, KID1, KID2, KID3 are respectively the ratio brake slope of each section, and wherein KID1 and KID3 device internal fixation are 0.2 and 0.7, and KID2 is adjusted by the user.IB1, IB2 are respectively keen current, and wherein IB1 device internal fixation is 0.5I
R2ln(I
R2lnBe the terminal secondary rated current of reactor), IB2 is adjusted by the user.I
CDBe differential starting current definite value.
5. method as claimed in claim 1, comprising the high value biased differential protection that is not subjected to the saturated locking of TA direct current, carry out corresponding action according to following formula and judge:
6. method as claimed in claim 1, wherein the criterion that TA is unusual is as follows:
1) self-produced zero stream of an end is big among the reactor first and last end TA, and self-produced zero stream of the other end is little;
2) among the reactor first and last end TA, the big end of zero stream has a phase current to reduce, the three-phase current no change of other phase of this end and the other end;
3) reactor first and last end three-phase totally six electric currents all less than 1.1/
R2ln
4) no residual voltage;
Wherein, whether the syllogic biased differential protection can be selected by control word by the user through the TA abnormal obliteration.
7. method as claimed in claim 1, wherein the criterion that the TA direct current is saturated is as follows:
1) phase current difference stream first-harmonic is greater than 0.15I
R2ln
2) the phase current difference flows 2 subharmonic ratio greater than 10%, and the triple-frequency harmonics ratio is less than 10%;
3) phase current difference stream waveform deflection time shaft one side, promptly | S
+-S
-| 〉=20%|S
++ S
-|, S wherein
+And S
-Be respectively positive sampled value integration and negative sampled value integration in differential current one cycle;
4) phase current is greater than 1.5I
R2lnThe time remove the saturated differentiation of TA direct current;
Wherein, declare and the saturated back of TA direct current locking syllogic biased differential protection.
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| CNB2003101224425A CN100399662C (en) | 2003-12-24 | 2003-12-24 | Digital high votage parallel reactor longitudinal protection with end braking |
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| CNB2003101224425A CN100399662C (en) | 2003-12-24 | 2003-12-24 | Digital high votage parallel reactor longitudinal protection with end braking |
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Cited By (12)
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| CN100449900C (en) * | 2006-11-22 | 2009-01-07 | 北京四方继保自动化股份有限公司 | High-voltage ac. controllable parallel-connection reactor high-differential protection method |
| CN100449899C (en) * | 2006-11-22 | 2009-01-07 | 北京四方继保自动化股份有限公司 | High-voltage AC. controllable parallel-connection reactor control winding zero-sequence protection method |
| CN102185292A (en) * | 2011-04-15 | 2011-09-14 | 中国南方电网有限责任公司超高压输电公司 | Direct current longitudinal differential protection method for use in direct current high-voltage power transmission lines |
| CN103760435A (en) * | 2013-12-31 | 2014-04-30 | 华北电力大学（保定） | Fault identification method for electric current semi-cycle absolute value integral differential formula of ratio restrain characteristics |
| CN104348135A (en) * | 2013-07-26 | 2015-02-11 | 南京南瑞继保电气有限公司 | Method for judging short circuit fault of control part of high-voltage controllable paralleling reactor |
| CN105071345A (en) * | 2015-07-31 | 2015-11-18 | 西安交通大学 | Differential protection hardware circuit with percentage differential and implementation method of differential protection hardware circuit |
| CN105337251A (en) * | 2015-11-11 | 2016-02-17 | 中国能源建设集团广东省电力设计研究院有限公司 | Parameter setting method and system of multi-slope differential protection |
| CN106972468A (en) * | 2017-04-13 | 2017-07-21 | 北京四方继保自动化股份有限公司 | A kind of method protected by maximum fault current locking differential current |
| CN110082644A (en) * | 2019-05-23 | 2019-08-02 | 国电南瑞科技股份有限公司 | Relay protection circuit CT broken string recognition methods and fault positioning method for transmission line |
| CN110609201A (en) * | 2019-09-25 | 2019-12-24 | 特变电工南京智能电气有限公司 | Line breakage judging method |
| CN112415435A (en) * | 2020-10-29 | 2021-02-26 | 云南电网有限责任公司 | Detection method for secondary loop of parallel reactor protection device |
| CN112782494A (en) * | 2019-11-05 | 2021-05-11 | 南京南瑞继保电气有限公司 | Saturation identification method and device for shunt reactor |
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| JPH06253448A (en) * | 1993-03-01 | 1994-09-09 | Nissin Electric Co Ltd | Protective relay for shunt reactor of phase modifying equipment |
| CN1310390C (en) * | 2002-06-02 | 2007-04-11 | 国电南京自动化股份有限公司 | Fault-tolerant quick discrimination method for differential protection of parallel reactor |
| CN100421326C (en) * | 2003-05-28 | 2008-09-24 | 北京四方继保自动化有限公司 | Method for different protection using wave-shaping method |
-
2003
- 2003-12-24 CN CNB2003101224425A patent/CN100399662C/en not_active Expired - Lifetime
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| CN100449899C (en) * | 2006-11-22 | 2009-01-07 | 北京四方继保自动化股份有限公司 | High-voltage AC. controllable parallel-connection reactor control winding zero-sequence protection method |
| CN100449900C (en) * | 2006-11-22 | 2009-01-07 | 北京四方继保自动化股份有限公司 | High-voltage ac. controllable parallel-connection reactor high-differential protection method |
| CN102185292A (en) * | 2011-04-15 | 2011-09-14 | 中国南方电网有限责任公司超高压输电公司 | Direct current longitudinal differential protection method for use in direct current high-voltage power transmission lines |
| CN104348135A (en) * | 2013-07-26 | 2015-02-11 | 南京南瑞继保电气有限公司 | Method for judging short circuit fault of control part of high-voltage controllable paralleling reactor |
| CN104348135B (en) * | 2013-07-26 | 2017-10-13 | 南京南瑞继保电气有限公司 | A kind of method for judging high pressure controllable parallel reactors control section short trouble |
| CN103760435A (en) * | 2013-12-31 | 2014-04-30 | 华北电力大学（保定） | Fault identification method for electric current semi-cycle absolute value integral differential formula of ratio restrain characteristics |
| CN103760435B (en) * | 2013-12-31 | 2016-04-13 | 华北电力大学（保定） | The fault identification method for electric current semi-cycle absolute value integral differential of ratio-restrained characteristic |
| CN105071345A (en) * | 2015-07-31 | 2015-11-18 | 西安交通大学 | Differential protection hardware circuit with percentage differential and implementation method of differential protection hardware circuit |
| CN105337251B (en) * | 2015-11-11 | 2018-09-28 | 中国能源建设集团广东省电力设计研究院有限公司 | The parameter tuning method and system of multi slope differential protection |
| CN105337251A (en) * | 2015-11-11 | 2016-02-17 | 中国能源建设集团广东省电力设计研究院有限公司 | Parameter setting method and system of multi-slope differential protection |
| CN106972468A (en) * | 2017-04-13 | 2017-07-21 | 北京四方继保自动化股份有限公司 | A kind of method protected by maximum fault current locking differential current |
| CN110082644A (en) * | 2019-05-23 | 2019-08-02 | 国电南瑞科技股份有限公司 | Relay protection circuit CT broken string recognition methods and fault positioning method for transmission line |
| CN110082644B (en) * | 2019-05-23 | 2022-03-15 | 国电南瑞科技股份有限公司 | Relay protection circuit CT disconnection identification method and power transmission line fault location method |
| CN110609201A (en) * | 2019-09-25 | 2019-12-24 | 特变电工南京智能电气有限公司 | Line breakage judging method |
| CN110609201B (en) * | 2019-09-25 | 2022-02-08 | 特变电工南京智能电气有限公司 | Line breakage judging method |
| CN112782494A (en) * | 2019-11-05 | 2021-05-11 | 南京南瑞继保电气有限公司 | Saturation identification method and device for shunt reactor |
| CN112782494B (en) * | 2019-11-05 | 2023-10-17 | 南京南瑞继保电气有限公司 | Saturation identification method and device for shunt reactor |
| CN112415435A (en) * | 2020-10-29 | 2021-02-26 | 云南电网有限责任公司 | Detection method for secondary loop of parallel reactor protection device |
| CN112415435B (en) * | 2020-10-29 | 2024-01-19 | 云南电网有限责任公司 | Detection method for secondary loop of parallel reactor protection device |
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